Troubleshooting Melamine Chip-Out Around Bore Holes

Drill bit type and drilling speed control can reduce chipout on two-sided melamine panels, and there are also touch-up solutions for minor chipping problems. February 26, 2007

QuestionWe are doing closets made of mostly white melamine and when we linebore all the way through, some of the holes chip on the back side. Is there an easy way to touch up around the line bore holes?

From contributor M:Little chips along the edge of a board can easily be fixed with Seamfil, but a chipped line boring hole is another story. Do what you can to fix what you have for now, but you must address the problem. What are you using to do the line boring? If you are using a line boring machine, you should have a hydro damper to slow the feed down as it pokes through. Our Gannomat has this feature. But we do all our closet sides on our Weeke. We have switched to solid carbide V point drills for all our line boring, both through and to depth. A tiny chip here or there is not too bad, but anything you can notice from a few feet away means it is time to re-sharpen.
From contributor U:When drilling a center partition that gets line boring on both sides of a single panel, I'd see chipping on the bottoms too. A v-tipped carbide bit definitely helps, and so does judicious application of Bic Wite-Out.

However, for high-end applications where Wite-Out won't fly, I'm now drilling halfway through the panel, and then flipping it to finish the line boring. It takes just an extra minute, and guarantees a chip-free hole on both sides of the panel. (Our line boring is done on a Speedy207.)

From contributor L:So what do you do to fix gray, almond, antique white, summerflame, pearwood, black and other colors?
From the original questioner:Thanks for the responses. We are using a CNC router multi-spindle boring head to do the line boring. I know I get perfect holes on both sides when my spoilboard is fresh, but when you start nesting sheets and the holes are a little off of where the previous sheet was, we get chipping on the back due to the fact that there is nothing backing up the sheet on the back side. I'll replace the bits and see if I get any better results.
From contributor M:I have found that the solid carbide bits last 10 times longer than the carbide tipped. On your CNC machine, can you slow the feed rate down during the drill cycle when the bit would start to poke through the back side? On our Weeke, we just choose a (slow-fast-slow) cycle and when our tooling is sharp, we get no chipping on either side of the board. And on a pod type machine there is no spoil board anyway.
From contributor L:All or our line boring is done on a Komo with the multi-spindle drill block, through-bore (Vee) bits and slow down at exit. Good results, and bits last quite awhile.
From the original questioner:Thanks for all the responses. I will change the drill head over to the vee bits and see if that make a difference.
From contributor T:Try using Sandford Mean Streak. It comes in a marker pen and works great.

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